基于阳离子型共轭聚合物和核酸适配体的高灵敏铅离子快速检测方法  

Rapid Detection of Lead Ion (Ⅱ) Based on Cationic Conjugated Polymer and Aptamer

作　　者：刘兴奋[1] 王亚腾 华笑笑 黄艳琴[1] 冯晓苗[1] 范曲立[1] 黄维[1,2] 

机构地区：[1]南京邮电大学信息材料与纳米技术研究院,有机电子与信息显示国家重点实验室培育基地,江苏省有机电子和信息显示协同创新中心,南京210023 [2]南京工业大学先进材料研究院,江苏省柔性电子重点实验室,先进生物与化学制造协同创新中心,南京211816

出　　处：《分析化学》2016年第7期1092-1098,共7页Chinese Journal of Analytical Chemistry

基　　金：国家重点基础研究发展计划项目(No.2012CB933301、2012CB723402);国家自然科学基金项目(Nos.21005040、51173080);“有机与生物光电子学”教育部创新团队(No.IRT1148);江苏高校优势学科建设工程资助项目;江苏省自然科学基金(BK20141424);江苏省普通高校研究生科研创新计划项目(CXLX12_0792);南京邮电大学校科研项目(NY215171)资助~~

摘　　要：建立了基于主链含芴的阳离子型对芳撑乙炔衍生物(poly{[9,9-bis(6'-(N,N,N-diethylmethyl ammonium)hexyl)-2,7-fluorenyleneethynylene]-alt-co-[2,5-bis(3'-(N,N,N-diethylmethylammonium)-1'-oxapropyl)-1,4-phenylene]tetraiodide},PFEP)和核酸适配体快速检测Pb^(2+)的新方法。使用选择性更高的核酸适配体序列,有效降低了Hg^(2+)对Pb^(2+)检测的干扰,提高了检测的选择性和灵敏度。用于识别Pb^(2+)的核酸探针(TBAA)末端用荧光素标记(5'-6-FAM-GGAAGGTGTGGAAGG-3')。当其与Pb^(2+)发生特异性结合时,形成电荷密度高于单链DNA的G-四链体结构,与PFEP之间的静电作用增强,使能量供体(聚合物)与受体(荧光素)之间的距离拉近,发生更高效的荧光共振能量转移(Fluorescence resonance energy transfer,FRET)。其它金属离子由于不能和TBAA结合,且金属离子本身对聚合物和荧光素的荧光有一定程度的猝灭,因此其FRET信号远低于空白对照。本方法快速、灵敏,几分钟内即可完成检测,常见金属离子均不干扰检测。对湖水中Pb^(2+)的检测限为1 nmol/L,远低于饮用水国家标准中对Pb^(2+)浓度的限量标准。本方法为水中Pb^(2+)的检测提供了一种简便、快速、高效的新方法。A sensitive method for Pb^2＋ detection based on a cationic conjugated polymer and aptamer was established. By selecting a more specific aptamer probe, the interference of Pb^2＋ detection from Hg^2＋ was eliminated remarkably. The probe for Pb^2＋recognition and combination is a single stranded oligonucleotide labeled with fluorescein （TBAA, 5＇-6-FAM-GGAAGGTGTGGAAGG-3＇）. When combining with Pb^2＋ with high specificity, the random coiled probe changed to a G-quadruplex with higher charge density, which enhanced the electrostatic interactions between the oligonucleotide and cationic conjugated polymer, thus the two fluorophores were in more close proximity, leading to a significantly increased fluorescence resonance energy transfer （FRET） signal. However, other non-target metal ions produced much lower FRET signals because they could not combine with the probe and thus quenched the fluorescence of the conjugated polymer and fluorescein. This method was rapid, highly specific and sensitive, and the common metal ions including Li^＋, Na^＋, K^＋, Ca^2＋, Mg^2＋, Ba^2＋, Fe^2＋, Co^2＋, Ni^2＋, Cu^2＋, Zn^2＋, Cd^2＋ and Hg^2＋ exhibited no influence on the detection of Pb^2＋. The limit of detection for Pb^2＋ in lake water was estimated to be 1 nmol/L （3σ）, which was far below the maximum permitted level of Pb^2＋ in drink water regulated drinking water quality. Therefore, this FRET-based method provides a new method for detection of Pb^2＋ in various source of water. by the national standard for simple, rapid, and efficient

关 键 词：阳离子型共轭聚合物 核酸适配体 铅离子 荧光共振能量转移 

分 类 号：O657.3[理学—分析化学]